Workshop on Workshop on Novelty and Diversity in Recommender Systems

Most research and development efforts in the Recommender Systems field have been focused on accuracy in predicting and matching user interests. However there is a growing realization that there is more than accuracy to the practical effectiveness and added-value of recommendation. In particular, novelty and diversity have been identified as key dimensions of recommendation utility in real scenarios, and a fundamental research direction to keep making progress in the field.

Novelty is indeed essential to recommendation: in many, if not most scenarios, the whole point of recommendation is inherently linked to a notion of discovery, as recommendation makes most sense when it exposes the user to a relevant experience that she would not have found, or thought of by herself. Not only does a varied recommendation provide in itself for a richer user experience. Given the inherent uncertainty in user interest prediction, avoiding a too narrow array of choice is generally a good approach to enhance the chances that the user is pleased by at least some recommended item. Sales diversity may enhance businesses as well, leveraging revenues from market niches. The challenge is to enhance these aspects while still delivering quality and achieving a fair match of the user’s interests.

DiveRS 2011 aimed to gather researchers and practitioners interested in the role of novelty and diversity in recommender systems, in a forum where participants can discuss problems, exchange ideas, and find opportunities for collaboration. The workshop seeked to advance towards a better understanding of what novelty and diversity are, how they can improve the effectiveness of recommendation methods and the utility of their outputs. We aimed to identify open problems, relevant research directions, and opportunities for innovation in the recommendation business in this area.